Testdisk screwed up my external HDD

How to use TestDisk to recover lost partition
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Fiona
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Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: Testdisk screwed up my external HDD

#11 Postby Fiona » 03 May 2012, 06:24

Would it be possible to use Delete in TestDisk?
It's going to delete your partition table.
But Quick Search should find them again.
Did you Backup your partition table using TestDisk Analyse / Backup?
It's also a fast thing to restore (but only in case).
Also in your disk management click Actionj and Rescan Disks.
This should nount your disk agin.
Did you already test your disk on another computer?
Because TestDisk displays your partition table correctly.

Fiona

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FixingProblems
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Joined: 29 Apr 2012, 16:11

Re: Testdisk screwed up my external HDD

#12 Postby FixingProblems » 04 May 2012, 04:19

Fiona wrote:Would it be possible to use Delete in TestDisk?
It's going to delete your partition table.
But Quick Search should find them again.
Did you Backup your partition table using TestDisk Analyse / Backup?

Yes, I backed up my partition table after writing partition structure to disk with testdisk (which I'm assuming rewrites the partition table, does it not? if that is the case, then why delete it again?). Also note I may have installed PC-BSD (on that "FreeBSD" partition you see in the Testdisk screenshot) using the GUID partition type instead of MBR, which would explain why Windows is seeing the disk as a single volume, and not seeing the partitions on there (at least according to someone I'm discussing the same problem with on another forums), since GUID "has some very rudimentary MBR emulation to protect the partition from being overwritten. Basically, it'll show the entire drive as one partition of unknown type (instead of free or unformatted)." (in the words of that certain someone, who just happens to be Computer Guru at Neosmart.net, creator of EasyBCD). :mrgreen: I asked him if there is a way to change a GUID partition to MBR after-the-fact without damaging my PC-BSD installation, and was told that he didn't know of any utilities out there that could automate this process (though I want to take a look at it with Partition Magic, in hopes that it might be able to), though he said Testdisk might be able to do it if I forced it to see the disk as MBR. I also want to say I am able to boot into PC-BSD using my 3rd party boot manager (BootIt NG) on old computer running multiboot of XP, Ubuntu (and Vista, though I hardly ever get on that), though I cannot access the other partitions on that external USB hard drive from PC-BSD, and also from BING's Partition Work window, when I click the Properties button with the PC-BSD partition selected, it shows the partition as having a start position number higher than the end position number(?), though I noticed that from testdisk, the partition looks normal except for the fact that it doesn't directly follow the second partition on the hard disk (and looking at it from BING, there isn't any visible free space in between either). So obviously, there is some funny business going on with my PC-BSD partition, and like mentioned before, I believe that is due to possibly installing PC-BSD using GUID partition type instead of MBR.
It's also a fast thing to restore (but only in case).
Also in your disk management click Actionj and Rescan Disks.
This should mount your disk agin.

Good idea. I will try that, and see if the hard disk is detected correctly after in Windows.
Also note that just a few minutes ago, I booted Ubuntu on my old computer, and then connected my USB hard drive we're discussing. And now I am able to see in Ubuntu's "Computer" window, the first and second partitions on that hard disk. I can even mount the second partition (which stores image backups), and see its files. However, the first partition, I can open and browse, but Ubuntu reports its empty, with 0 items, even though I know there were files on there before as that was my main partition on the hard drive (which was originally intended for just data, but I decided to install PC-BSD on it later, on that 3rd partition you see), and I remember looking at its files earlier with Testdisk. But now, with Testdisk in Ubuntu, I do not even have an option to list files in the [ Advanced ] screen when selecting any of the partitions on the hard drive. So I'm worried I may have lost some data now!??
Did you already test your disk on another computer?
Because TestDisk displays your partition table correctly.

Fiona


EDIT: Ok, nevermind on the last part. I booted into my XP which has the latest Testdisk, and looked at the partitions again under Testdisks's "Advanced" menu, and this time I could see the List option for the first partition, though it doesn't show that option for the other two partitions for some reason, so that is strange. And listing the files shows stuff on the first partition like expected, so evidently they're still there, but Ubuntu can't see them for some reason. So anyway, I'm off to go check out my hard drive through Mini Tool Partition Wizard Bootable CD. Maybe that will shed some more light on this matter...and give me some clue on how to solve the problem.

User avatar
Fiona
Posts: 2839
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: Testdisk screwed up my external HDD

#13 Postby Fiona » 05 May 2012, 11:06

It looks like that MBR emulation etc.. doesn't work.
Windows displays your disk as basic, one partition using the whole space and unformatted.
I assume that it's not possible to use a disk as GPT and Intel MBR.
It should be one disk type.
It means either GPT or MBR.
It'd be a reliable solution.
First of all, I would backup data.
If you'd like to keep GPT, use windows disk management to convert it.
It might be possible that windows creates an ESP or MSR partition and a MS data- partition?
http://msdn.microsoft.com/en-us/windows ... e/gg463525

Fiona

FixingProblems
Posts: 8
Joined: 29 Apr 2012, 16:11

Re: Testdisk screwed up my external HDD

#14 Postby FixingProblems » 05 May 2012, 17:14

Fiona wrote:It looks like that MBR emulation etc.. doesn't work.
Windows displays your disk as basic, one partition using the whole space and unformatted.
I assume that it's not possible to use a disk as GPT and Intel MBR.
It should be one disk type.
It means either GPT or MBR.
It'd be a reliable solution.
First of all, I would backup data.
If you'd like to keep GPT, use windows disk management to convert it.
It might be possible that windows creates an ESP or MSR partition and a MS data- partition?
http://msdn.microsoft.com/en-us/windows ... e/gg463525

Fiona

Ok, thanks for the link.
Looking at it, I learned a few things about GPT.
According to that page, Windows XP 32 bit (which is what I have) cannot even read a GPT partitioned disk, though the 64 bit version can use it for data only. And yes, you are right. A disk cannot be both GPT and MBR at the same time. It has to be one or the other. However, on GPT disks, there is a protective MBR area that exists on a GPT partition table for backward compatibility with disk management utilities that operate on MBR. The protective MBR contains one type 0xEE partition that spans the disk, which explains why Disk Management sees my hard drive that way. So I guess I should have been telling Testdisk the disk was GPT, not Intel MBR...my bad. So now I'm running Testdisk's Analyze-->Quick Search again with the disk being selected as GPT, not MBR, and now things are beginning to look different. Before running the Quick Search, the partition table showed only one partition with a bad structure, or some such thing, but now its located my [Iomega_HDD] (first partition) and [NEW MBR ENT] (second partition) partitions, both of which it says is for "MS DATA", but it has yet to locate my PC-BSD partition (though the search is still running, though slower than before). So hopefully, it will locate the last one, and I can choose to write the partition structure to disk again, thus making it a GPT disk once more instead of MBR. At least, that is what I hope...
Another thing I learned from that page is you cannot convert a GPT disk to MBR without deleting the partitions on there, and thus losing all the data on the hard drive, so I don't want to take that route, even if I could find a utility which could do it. Disk Management can't convert GPT to MBR, btw.


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